Is There an Age Limit for a Trial of Vaginal Delivery in Nulliparous Women?

Abstract

The number of nulliparous women over the age of 35 is consistently increasing, and the optimal delivery strategy is a subject of ongoing discussion. This study compares perinatal outcomes in nulliparous women aged ≥35 years undergoing a trial of labor (TOL) versus a planned cesarean delivery (CD). A retrospective cohort study including all nulliparous women ≥ 35 years who delivered a single term fetus at a single center between 2007-2019. We compared obstetric and perinatal outcomes according to mode of delivery-TOL versus a planned CD, in three different age groups: (1) 35-37 years, (2) 38-40 years, and (3) >40 years. Out of 103,920 deliveries during the study period, 3034 women met the inclusion criteria. Of them, 1626 (53.59%) were 35-37 years old (group 1), 848 (27.95%) were 38-40 (group 2), and 560 (18.46%) were >40 years (group 3). TOL rates decreased as age increased: 87.7% in group 1, 79.3% in group 2, and 50.1% in group 3, p < 0.001. Rates of successful vaginal delivery were 83.4% in group 1, 79.0% in group 2, and 69.4% in group 3, p < 0.001). Neonatal outcomes were comparable between a TOL and a planned CD. Using multivariate logistic regression, maternal age was found to be independently associated with slightly increased odds for a failed TOL (aOR = 1.13, CI 95% 1.067-1.202). A TOL at advanced maternal age appears to be safe, with considerable success rates. As maternal age advances, there is a small additive risk of intrapartum CD.